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android / platform / libcore / c3041101495 / . / jdk / src / java.base / share / classes / java / lang / invoke / MethodHandleImpl.java
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/*
* Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang.invoke;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.function.Function;
import jdk.internal.vm.annotation.Stable;
import sun.invoke.empty.Empty;
import sun.invoke.util.ValueConversions;
import sun.invoke.util.VerifyType;
import sun.invoke.util.Wrapper;
import sun.reflect.CallerSensitive;
import sun.reflect.Reflection;
import static java.lang.invoke.LambdaForm.*;
import static java.lang.invoke.MethodHandleStatics.*;
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
/**
* Trusted implementation code for MethodHandle.
* @author jrose
*/
/*non-public*/ abstract class MethodHandleImpl {
// Do not adjust this except for special platforms:
private static final int MAX_ARITY;
static {
final Object[] values = { 255 };
AccessController.doPrivileged(new PrivilegedAction<>() {
@Override
public Void run() {
values[0] = Integer.getInteger(MethodHandleImpl.class.getName()+".MAX_ARITY", 255);
return null;
}
});
MAX_ARITY = (Integer) values[0];
}
/// Factory methods to create method handles:
static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, boolean isSetter) {
if (arrayClass == Object[].class)
return (isSetter ? ArrayAccessor.OBJECT_ARRAY_SETTER : ArrayAccessor.OBJECT_ARRAY_GETTER);
if (!arrayClass.isArray())
throw newIllegalArgumentException("not an array: "+arrayClass);
MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
int cacheIndex = (isSetter ? ArrayAccessor.SETTER_INDEX : ArrayAccessor.GETTER_INDEX);
MethodHandle mh = cache[cacheIndex];
if (mh != null) return mh;
mh = ArrayAccessor.getAccessor(arrayClass, isSetter);
MethodType correctType = ArrayAccessor.correctType(arrayClass, isSetter);
if (mh.type() != correctType) {
assert(mh.type().parameterType(0) == Object[].class);
assert((isSetter ? mh.type().parameterType(2) : mh.type().returnType()) == Object.class);
assert(isSetter || correctType.parameterType(0).getComponentType() == correctType.returnType());
// safe to view non-strictly, because element type follows from array type
mh = mh.viewAsType(correctType, false);
}
mh = makeIntrinsic(mh, (isSetter ? Intrinsic.ARRAY_STORE : Intrinsic.ARRAY_LOAD));
// Atomically update accessor cache.
synchronized(cache) {
if (cache[cacheIndex] == null) {
cache[cacheIndex] = mh;
} else {
// Throw away newly constructed accessor and use cached version.
mh = cache[cacheIndex];
}
}
return mh;
}
static final class ArrayAccessor {
/// Support for array element access
static final int GETTER_INDEX = 0, SETTER_INDEX = 1, INDEX_LIMIT = 2;
static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
= new ClassValue<MethodHandle[]>() {
@Override
protected MethodHandle[] computeValue(Class<?> type) {
return new MethodHandle[INDEX_LIMIT];
}
};
static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER;
static {
MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, false), Intrinsic.ARRAY_LOAD);
cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, true), Intrinsic.ARRAY_STORE);
assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
}
static int getElementI(int[] a, int i) { return a[i]; }
static long getElementJ(long[] a, int i) { return a[i]; }
static float getElementF(float[] a, int i) { return a[i]; }
static double getElementD(double[] a, int i) { return a[i]; }
static boolean getElementZ(boolean[] a, int i) { return a[i]; }
static byte getElementB(byte[] a, int i) { return a[i]; }
static short getElementS(short[] a, int i) { return a[i]; }
static char getElementC(char[] a, int i) { return a[i]; }
static Object getElementL(Object[] a, int i) { return a[i]; }
static void setElementI(int[] a, int i, int x) { a[i] = x; }
static void setElementJ(long[] a, int i, long x) { a[i] = x; }
static void setElementF(float[] a, int i, float x) { a[i] = x; }
static void setElementD(double[] a, int i, double x) { a[i] = x; }
static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
static void setElementS(short[] a, int i, short x) { a[i] = x; }
static void setElementC(char[] a, int i, char x) { a[i] = x; }
static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
static String name(Class<?> arrayClass, boolean isSetter) {
Class<?> elemClass = arrayClass.getComponentType();
if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
return (!isSetter ? "getElement" : "setElement") + Wrapper.basicTypeChar(elemClass);
}
static MethodType type(Class<?> arrayClass, boolean isSetter) {
Class<?> elemClass = arrayClass.getComponentType();
Class<?> arrayArgClass = arrayClass;
if (!elemClass.isPrimitive()) {
arrayArgClass = Object[].class;
elemClass = Object.class;
}
return !isSetter ?
MethodType.methodType(elemClass, arrayArgClass, int.class) :
MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
}
static MethodType correctType(Class<?> arrayClass, boolean isSetter) {
Class<?> elemClass = arrayClass.getComponentType();
return !isSetter ?
MethodType.methodType(elemClass, arrayClass, int.class) :
MethodType.methodType(void.class, arrayClass, int.class, elemClass);
}
static MethodHandle getAccessor(Class<?> arrayClass, boolean isSetter) {
String name = name(arrayClass, isSetter);
MethodType type = type(arrayClass, isSetter);
try {
return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
} catch (ReflectiveOperationException ex) {
throw uncaughtException(ex);
}
}
}
/**
* Create a JVM-level adapter method handle to conform the given method
* handle to the similar newType, using only pairwise argument conversions.
* For each argument, convert incoming argument to the exact type needed.
* The argument conversions allowed are casting, boxing and unboxing,
* integral widening or narrowing, and floating point widening or narrowing.
* @param srcType required call type
* @param target original method handle
* @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
* @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
* @return an adapter to the original handle with the desired new type,
* or the original target if the types are already identical
* or null if the adaptation cannot be made
*/
static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
boolean strict, boolean monobox) {
MethodType dstType = target.type();
if (srcType == dstType)
return target;
return makePairwiseConvertByEditor(target, srcType, strict, monobox);
}
private static int countNonNull(Object[] array) {
int count = 0;
for (Object x : array) {
if (x != null) ++count;
}
return count;
}
static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
boolean strict, boolean monobox) {
Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
int convCount = countNonNull(convSpecs);
if (convCount == 0)
return target.viewAsType(srcType, strict);
MethodType basicSrcType = srcType.basicType();
MethodType midType = target.type().basicType();
BoundMethodHandle mh = target.rebind();
// FIXME: Reduce number of bindings when there is more than one Class conversion.
// FIXME: Reduce number of bindings when there are repeated conversions.
for (int i = 0; i < convSpecs.length-1; i++) {
Object convSpec = convSpecs[i];
if (convSpec == null) continue;
MethodHandle fn;
if (convSpec instanceof Class) {
fn = getConstantHandle(MH_cast).bindTo(convSpec);
} else {
fn = (MethodHandle) convSpec;
}
Class<?> newType = basicSrcType.parameterType(i);
if (--convCount == 0)
midType = srcType;
else
midType = midType.changeParameterType(i, newType);
LambdaForm form2 = mh.editor().filterArgumentForm(1+i, BasicType.basicType(newType));
mh = mh.copyWithExtendL(midType, form2, fn);
mh = mh.rebind();
}
Object convSpec = convSpecs[convSpecs.length-1];
if (convSpec != null) {
MethodHandle fn;
if (convSpec instanceof Class) {
if (convSpec == void.class)
fn = null;
else
fn = getConstantHandle(MH_cast).bindTo(convSpec);
} else {
fn = (MethodHandle) convSpec;
}
Class<?> newType = basicSrcType.returnType();
assert(--convCount == 0);
midType = srcType;
if (fn != null) {
mh = mh.rebind(); // rebind if too complex
LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
mh = mh.copyWithExtendL(midType, form2, fn);
} else {
LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
mh = mh.copyWith(midType, form2);
}
}
assert(convCount == 0);
assert(mh.type().equals(srcType));
return mh;
}
static MethodHandle makePairwiseConvertIndirect(MethodHandle target, MethodType srcType,
boolean strict, boolean monobox) {
assert(target.type().parameterCount() == srcType.parameterCount());
// Calculate extra arguments (temporaries) required in the names array.
Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
final int INARG_COUNT = srcType.parameterCount();
int convCount = countNonNull(convSpecs);
boolean retConv = (convSpecs[INARG_COUNT] != null);
boolean retVoid = srcType.returnType() == void.class;
if (retConv && retVoid) {
convCount -= 1;
retConv = false;
}
final int IN_MH = 0;
final int INARG_BASE = 1;
final int INARG_LIMIT = INARG_BASE + INARG_COUNT;
final int NAME_LIMIT = INARG_LIMIT + convCount + 1;
final int RETURN_CONV = (!retConv ? -1 : NAME_LIMIT - 1);
final int OUT_CALL = (!retConv ? NAME_LIMIT : RETURN_CONV) - 1;
final int RESULT = (retVoid ? -1 : NAME_LIMIT - 1);
// Now build a LambdaForm.
MethodType lambdaType = srcType.basicType().invokerType();
Name[] names = arguments(NAME_LIMIT - INARG_LIMIT, lambdaType);
// Collect the arguments to the outgoing call, maybe with conversions:
final int OUTARG_BASE = 0; // target MH is Name.function, name Name.arguments[0]
Object[] outArgs = new Object[OUTARG_BASE + INARG_COUNT];
int nameCursor = INARG_LIMIT;
for (int i = 0; i < INARG_COUNT; i++) {
Object convSpec = convSpecs[i];
if (convSpec == null) {
// do nothing: difference is trivial
outArgs[OUTARG_BASE + i] = names[INARG_BASE + i];
continue;
}
Name conv;
if (convSpec instanceof Class) {
Class<?> convClass = (Class<?>) convSpec;
conv = new Name(getConstantHandle(MH_cast), convClass, names[INARG_BASE + i]);
} else {
MethodHandle fn = (MethodHandle) convSpec;
conv = new Name(fn, names[INARG_BASE + i]);
}
assert(names[nameCursor] == null);
names[nameCursor++] = conv;
assert(outArgs[OUTARG_BASE + i] == null);
outArgs[OUTARG_BASE + i] = conv;
}
// Build argument array for the call.
assert(nameCursor == OUT_CALL);
names[OUT_CALL] = new Name(target, outArgs);
Object convSpec = convSpecs[INARG_COUNT];
if (!retConv) {
assert(OUT_CALL == names.length-1);
} else {
Name conv;
if (convSpec == void.class) {
conv = new Name(LambdaForm.constantZero(BasicType.basicType(srcType.returnType())));
} else if (convSpec instanceof Class) {
Class<?> convClass = (Class<?>) convSpec;
conv = new Name(getConstantHandle(MH_cast), convClass, names[OUT_CALL]);
} else {
MethodHandle fn = (MethodHandle) convSpec;
if (fn.type().parameterCount() == 0)
conv = new Name(fn); // don't pass retval to void conversion
else
conv = new Name(fn, names[OUT_CALL]);
}
assert(names[RETURN_CONV] == null);
names[RETURN_CONV] = conv;
assert(RETURN_CONV == names.length-1);
}
LambdaForm form = new LambdaForm("convert", lambdaType.parameterCount(), names, RESULT);
return SimpleMethodHandle.make(srcType, form);
}
static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
boolean strict, boolean monobox) {
final int INARG_COUNT = srcType.parameterCount();
Object[] convSpecs = new Object[INARG_COUNT+1];
for (int i = 0; i <= INARG_COUNT; i++) {
boolean isRet = (i == INARG_COUNT);
Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
convSpecs[i] = valueConversion(src, dst, strict, monobox);
}
}
return convSpecs;
}
static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
boolean strict) {
return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
}
/**
* Find a conversion function from the given source to the given destination.
* This conversion function will be used as a LF NamedFunction.
* Return a Class object if a simple cast is needed.
* Return void.class if void is involved.
*/
static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
if (dst == void.class)
return dst;
MethodHandle fn;
if (src.isPrimitive()) {
if (src == void.class) {
return void.class; // caller must recognize this specially
} else if (dst.isPrimitive()) {
// Examples: int->byte, byte->int, boolean->int (!strict)
fn = ValueConversions.convertPrimitive(src, dst);
} else {
// Examples: int->Integer, boolean->Object, float->Number
Wrapper wsrc = Wrapper.forPrimitiveType(src);
fn = ValueConversions.boxExact(wsrc);
assert(fn.type().parameterType(0) == wsrc.primitiveType());
assert(fn.type().returnType() == wsrc.wrapperType());
if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
// Corner case, such as int->Long, which will probably fail.
MethodType mt = MethodType.methodType(dst, src);
if (strict)
fn = fn.asType(mt);
else
fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
}
}
} else if (dst.isPrimitive()) {
Wrapper wdst = Wrapper.forPrimitiveType(dst);
if (monobox || src == wdst.wrapperType()) {
// Use a strongly-typed unboxer, if possible.
fn = ValueConversions.unboxExact(wdst, strict);
} else {
// Examples: Object->int, Number->int, Comparable->int, Byte->int
// must include additional conversions
// src must be examined at runtime, to detect Byte, Character, etc.
fn = (strict
? ValueConversions.unboxWiden(wdst)
: ValueConversions.unboxCast(wdst));
}
} else {
// Simple reference conversion.
// Note: Do not check for a class hierarchy relation
// between src and dst. In all cases a 'null' argument
// will pass the cast conversion.
return dst;
}
assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
return fn;
}
static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
MethodType type = target.type();
int last = type.parameterCount() - 1;
if (type.parameterType(last) != arrayType)
target = target.asType(type.changeParameterType(last, arrayType));
target = target.asFixedArity(); // make sure this attribute is turned off
return new AsVarargsCollector(target, arrayType);
}
private static final class AsVarargsCollector extends DelegatingMethodHandle {
private final MethodHandle target;
private final Class<?> arrayType;
private @Stable MethodHandle asCollectorCache;
AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
this(target.type(), target, arrayType);
}
AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
super(type, target);
this.target = target;
this.arrayType = arrayType;
this.asCollectorCache = target.asCollector(arrayType, 0);
}
@Override
public boolean isVarargsCollector() {
return true;
}
@Override
protected MethodHandle getTarget() {
return target;
}
@Override
public MethodHandle asFixedArity() {
return target;
}
@Override
MethodHandle setVarargs(MemberName member) {
if (member.isVarargs()) return this;
return asFixedArity();
}
@Override
public MethodHandle asTypeUncached(MethodType newType) {
MethodType type = this.type();
int collectArg = type.parameterCount() - 1;
int newArity = newType.parameterCount();
if (newArity == collectArg+1 &&
type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
// if arity and trailing parameter are compatible, do normal thing
return asTypeCache = asFixedArity().asType(newType);
}
// check cache
MethodHandle acc = asCollectorCache;
if (acc != null && acc.type().parameterCount() == newArity)
return asTypeCache = acc.asType(newType);
// build and cache a collector
int arrayLength = newArity - collectArg;
MethodHandle collector;
try {
collector = asFixedArity().asCollector(arrayType, arrayLength);
assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
} catch (IllegalArgumentException ex) {
throw new WrongMethodTypeException("cannot build collector", ex);
}
asCollectorCache = collector;
return asTypeCache = collector.asType(newType);
}
@Override
boolean viewAsTypeChecks(MethodType newType, boolean strict) {
super.viewAsTypeChecks(newType, true);
if (strict) return true;
// extra assertion for non-strict checks:
assert (type().lastParameterType().getComponentType()
.isAssignableFrom(
newType.lastParameterType().getComponentType()))
: Arrays.asList(this, newType);
return true;
}
}
/** Factory method: Spread selected argument. */
static MethodHandle makeSpreadArguments(MethodHandle target,
Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
MethodType targetType = target.type();
for (int i = 0; i < spreadArgCount; i++) {
Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
if (arg == null) arg = Object.class;
targetType = targetType.changeParameterType(spreadArgPos + i, arg);
}
target = target.asType(targetType);
MethodType srcType = targetType
.replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
// Now build a LambdaForm.
MethodType lambdaType = srcType.invokerType();
Name[] names = arguments(spreadArgCount + 2, lambdaType);
int nameCursor = lambdaType.parameterCount();
int[] indexes = new int[targetType.parameterCount()];
for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
Class<?> src = lambdaType.parameterType(i);
if (i == spreadArgPos) {
// Spread the array.
MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
Name array = names[argIndex];
names[nameCursor++] = new Name(NF_checkSpreadArgument, array, spreadArgCount);
for (int j = 0; j < spreadArgCount; i++, j++) {
indexes[i] = nameCursor;
names[nameCursor++] = new Name(aload, array, j);
}
} else if (i < indexes.length) {
indexes[i] = argIndex;
}
}
assert(nameCursor == names.length-1); // leave room for the final call
// Build argument array for the call.
Name[] targetArgs = new Name[targetType.parameterCount()];
for (int i = 0; i < targetType.parameterCount(); i++) {
int idx = indexes[i];
targetArgs[i] = names[idx];
}
names[names.length - 1] = new Name(target, (Object[]) targetArgs);
LambdaForm form = new LambdaForm("spread", lambdaType.parameterCount(), names);
return SimpleMethodHandle.make(srcType, form);
}
static void checkSpreadArgument(Object av, int n) {
if (av == null) {
if (n == 0) return;
} else if (av instanceof Object[]) {
int len = ((Object[])av).length;
if (len == n) return;
} else {
int len = java.lang.reflect.Array.getLength(av);
if (len == n) return;
}
// fall through to error:
throw newIllegalArgumentException("array is not of length "+n);
}
/** Factory method: Collect or filter selected argument(s). */
static MethodHandle makeCollectArguments(MethodHandle target,
MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
MethodType targetType = target.type(); // (a..., c, [b...])=>r
MethodType collectorType = collector.type(); // (b...)=>c
int collectArgCount = collectorType.parameterCount();
Class<?> collectValType = collectorType.returnType();
int collectValCount = (collectValType == void.class ? 0 : 1);
MethodType srcType = targetType // (a..., [b...])=>r
.dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
if (!retainOriginalArgs) { // (a..., b...)=>r
srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterList());
}
// in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
// out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
// out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
// Now build a LambdaForm.
MethodType lambdaType = srcType.invokerType();
Name[] names = arguments(2, lambdaType);
final int collectNamePos = names.length - 2;
final int targetNamePos = names.length - 1;
Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
// Build argument array for the target.
// Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
// Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
Name[] targetArgs = new Name[targetType.parameterCount()];
int inputArgPos = 1; // incoming LF args to copy to target
int targetArgPos = 0; // fill pointer for targetArgs
int chunk = collectArgPos; // |headArgs|
System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
inputArgPos += chunk;
targetArgPos += chunk;
if (collectValType != void.class) {
targetArgs[targetArgPos++] = names[collectNamePos];
}
chunk = collectArgCount;
if (retainOriginalArgs) {
System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
targetArgPos += chunk; // optionally pass on the collected chunk
}
inputArgPos += chunk;
chunk = targetArgs.length - targetArgPos; // all the rest
System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
names[targetNamePos] = new Name(target, (Object[]) targetArgs);
LambdaForm form = new LambdaForm("collect", lambdaType.parameterCount(), names);
return SimpleMethodHandle.make(srcType, form);
}
@LambdaForm.Hidden
static
MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
if (testResult) {
return target;
} else {
return fallback;
}
}
// Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
@LambdaForm.Hidden
@jdk.internal.HotSpotIntrinsicCandidate
static
boolean profileBoolean(boolean result, int[] counters) {
// Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
int idx = result ? 1 : 0;
try {
counters[idx] = Math.addExact(counters[idx], 1);
} catch (ArithmeticException e) {
// Avoid continuous overflow by halving the problematic count.
counters[idx] = counters[idx] / 2;
}
return result;
}
// Intrinsified by C2. Returns true if obj is a compile-time constant.
@LambdaForm.Hidden
@jdk.internal.HotSpotIntrinsicCandidate
static
boolean isCompileConstant(Object obj) {
return false;
}
static
MethodHandle makeGuardWithTest(MethodHandle test,
MethodHandle target,
MethodHandle fallback) {
MethodType type = target.type();
assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
MethodType basicType = type.basicType();
LambdaForm form = makeGuardWithTestForm(basicType);
BoundMethodHandle mh;
try {
if (PROFILE_GWT) {
int[] counts = new int[2];
mh = (BoundMethodHandle)
BoundMethodHandle.speciesData_LLLL().constructor().invokeBasic(type, form,
(Object) test, (Object) profile(target), (Object) profile(fallback), counts);
} else {
mh = (BoundMethodHandle)
BoundMethodHandle.speciesData_LLL().constructor().invokeBasic(type, form,
(Object) test, (Object) profile(target), (Object) profile(fallback));
}
} catch (Throwable ex) {
throw uncaughtException(ex);
}
assert(mh.type() == type);
return mh;
}
static
MethodHandle profile(MethodHandle target) {
if (DONT_INLINE_THRESHOLD >= 0) {
return makeBlockInliningWrapper(target);
} else {
return target;
}
}
/**
* Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
* Corresponding LambdaForm has @DontInline when compiled into bytecode.
*/
static
MethodHandle makeBlockInliningWrapper(MethodHandle target) {
LambdaForm lform;
if (DONT_INLINE_THRESHOLD > 0) {
lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target);
} else {
lform = Makers.PRODUCE_REINVOKER_FORM.apply(target);
}
return new CountingWrapper(target, lform,
Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM,
DONT_INLINE_THRESHOLD);
}
private final static class Makers {
/** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
@Override
public LambdaForm apply(MethodHandle target) {
return DelegatingMethodHandle.makeReinvokerForm(target,
MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, "reinvoker.dontInline", false,
DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
}
};
/** Constructs simple reinvoker lambda form for a particular method handle */
static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
@Override
public LambdaForm apply(MethodHandle target) {
return DelegatingMethodHandle.makeReinvokerForm(target,
MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
}
};
/** Maker of type-polymorphic varargs */
static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() {
@Override
protected MethodHandle[] computeValue(Class<?> type) {
return new MethodHandle[MAX_JVM_ARITY + 1];
}
};
}
/**
* Counting method handle. It has 2 states: counting and non-counting.
* It is in counting state for the first n invocations and then transitions to non-counting state.
* Behavior in counting and non-counting states is determined by lambda forms produced by
* countingFormProducer & nonCountingFormProducer respectively.
*/
static class CountingWrapper extends DelegatingMethodHandle {
private final MethodHandle target;
private int count;
private Function<MethodHandle, LambdaForm> countingFormProducer;
private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
private volatile boolean isCounting;
private CountingWrapper(MethodHandle target, LambdaForm lform,
Function<MethodHandle, LambdaForm> countingFromProducer,
Function<MethodHandle, LambdaForm> nonCountingFormProducer,
int count) {
super(target.type(), lform);
this.target = target;
this.count = count;
this.countingFormProducer = countingFromProducer;
this.nonCountingFormProducer = nonCountingFormProducer;
this.isCounting = (count > 0);
}
@Hidden
@Override
protected MethodHandle getTarget() {
return target;
}
@Override
public MethodHandle asTypeUncached(MethodType newType) {
MethodHandle newTarget = target.asType(newType);
MethodHandle wrapper;
if (isCounting) {
LambdaForm lform;
lform = countingFormProducer.apply(newTarget);
wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
} else {
wrapper = newTarget; // no need for a counting wrapper anymore
}
return (asTypeCache = wrapper);
}
// Customize target if counting happens for too long.
private int invocations = CUSTOMIZE_THRESHOLD;
private void maybeCustomizeTarget() {
int c = invocations;
if (c >= 0) {
if (c == 1) {
target.customize();
}
invocations = c - 1;
}
}
boolean countDown() {
int c = count;
maybeCustomizeTarget();
if (c <= 1) {
// Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
if (isCounting) {
isCounting = false;
return true;
} else {
return false;
}
} else {
count = c - 1;
return false;
}
}
@Hidden
static void maybeStopCounting(Object o1) {
CountingWrapper wrapper = (CountingWrapper) o1;
if (wrapper.countDown()) {
// Reached invocation threshold. Replace counting behavior with a non-counting one.
LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
wrapper.updateForm(lform);
}
}
static final NamedFunction NF_maybeStopCounting;
static {
Class<?> THIS_CLASS = CountingWrapper.class;
try {
NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
} catch (ReflectiveOperationException ex) {
throw newInternalError(ex);
}
}
}
static
LambdaForm makeGuardWithTestForm(MethodType basicType) {
LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
if (lform != null) return lform;
final int THIS_MH = 0; // the BMH_LLL
final int ARG_BASE = 1; // start of incoming arguments
final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
int nameCursor = ARG_LIMIT;
final int GET_TEST = nameCursor++;
final int GET_TARGET = nameCursor++;
final int GET_FALLBACK = nameCursor++;
final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
final int CALL_TEST = nameCursor++;
final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
final int SELECT_ALT = nameCursor++;
final int CALL_TARGET = nameCursor++;
assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
MethodType lambdaType = basicType.invokerType();
Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
BoundMethodHandle.SpeciesData data =
(GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
: BoundMethodHandle.speciesData_LLL();
names[THIS_MH] = names[THIS_MH].withConstraint(data);
names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
if (GET_COUNTERS != -1) {
names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
}
Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
// call test
MethodType testType = basicType.changeReturnType(boolean.class).basicType();
invokeArgs[0] = names[GET_TEST];
names[CALL_TEST] = new Name(testType, invokeArgs);
// profile branch
if (PROFILE != -1) {
names[PROFILE] = new Name(NF_profileBoolean, names[CALL_TEST], names[GET_COUNTERS]);
}
// call selectAlternative
names[SELECT_ALT] = new Name(getConstantHandle(MH_selectAlternative), names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
// call target or fallback
invokeArgs[0] = names[SELECT_ALT];
names[CALL_TARGET] = new Name(basicType, invokeArgs);
lform = new LambdaForm("guard", lambdaType.parameterCount(), names, /*forceInline=*/true);
return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
}
/**
* The LambdaForm shape for catchException combinator is the following:
* <blockquote><pre>{@code
* guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
* t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
* t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
* t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
* t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
* t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
* t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
* t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
* t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
* }</pre></blockquote>
*
* argL0 and argL2 are target and catcher method handles. argL1 is exception class.
* argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
* (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
*
* Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
* among catchException combinators with the same basic type.
*/
private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
MethodType lambdaType = basicType.invokerType();
LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
if (lform != null) {
return lform;
}
final int THIS_MH = 0; // the BMH_LLLLL
final int ARG_BASE = 1; // start of incoming arguments
final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
int nameCursor = ARG_LIMIT;
final int GET_TARGET = nameCursor++;
final int GET_CLASS = nameCursor++;
final int GET_CATCHER = nameCursor++;
final int GET_COLLECT_ARGS = nameCursor++;
final int GET_UNBOX_RESULT = nameCursor++;
final int BOXED_ARGS = nameCursor++;
final int TRY_CATCH = nameCursor++;
final int UNBOX_RESULT = nameCursor++;
Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
names[THIS_MH] = names[THIS_MH].withConstraint(data);
names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
// FIXME: rework argument boxing/result unboxing logic for LF interpretation
// t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
MethodType collectArgsType = basicType.changeReturnType(Object.class);
MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
Object[] args = new Object[invokeBasic.type().parameterCount()];
args[0] = names[GET_COLLECT_ARGS];
System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args);
// t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
names[TRY_CATCH] = new Name(NF_guardWithCatch, gwcArgs);
// t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
lform = new LambdaForm("guardWithCatch", lambdaType.parameterCount(), names);
return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
}
static
MethodHandle makeGuardWithCatch(MethodHandle target,
Class<? extends Throwable> exType,
MethodHandle catcher) {
MethodType type = target.type();
LambdaForm form = makeGuardWithCatchForm(type.basicType());
// Prepare auxiliary method handles used during LambdaForm interpretation.
// Box arguments and wrap them into Object[]: ValueConversions.array().
MethodType varargsType = type.changeReturnType(Object[].class);
MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
// Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore().
MethodHandle unboxResult;
Class<?> rtype = type.returnType();
if (rtype.isPrimitive()) {
if (rtype == void.class) {
unboxResult = ValueConversions.ignore();
} else {
Wrapper w = Wrapper.forPrimitiveType(type.returnType());
unboxResult = ValueConversions.unboxExact(w);
}
} else {
unboxResult = MethodHandles.identity(Object.class);
}
BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
BoundMethodHandle mh;
try {
mh = (BoundMethodHandle)
data.constructor().invokeBasic(type, form, (Object) target, (Object) exType, (Object) catcher,
(Object) collectArgs, (Object) unboxResult);
} catch (Throwable ex) {
throw uncaughtException(ex);
}
assert(mh.type() == type);
return mh;
}
/**
* Intrinsified during LambdaForm compilation
* (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
*/
@LambdaForm.Hidden
static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
Object... av) throws Throwable {
// Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
try {
return target.asFixedArity().invokeWithArguments(av);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.asFixedArity().invokeWithArguments(prepend(t, av));
}
}
/** Prepend an element {@code elem} to an {@code array}. */
@LambdaForm.Hidden
private static Object[] prepend(Object elem, Object[] array) {
Object[] newArray = new Object[array.length+1];
newArray[0] = elem;
System.arraycopy(array, 0, newArray, 1, array.length);
return newArray;
}
static
MethodHandle throwException(MethodType type) {
assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
int arity = type.parameterCount();
if (arity > 1) {
MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
mh = MethodHandles.dropArguments(mh, 1, type.parameterList().subList(1, arity));
return mh;
}
return makePairwiseConvert(NF_throwException.resolvedHandle(), type, false, true);
}
static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
static MethodHandle fakeMethodHandleInvoke(MemberName method) {
int idx;
assert(method.isMethodHandleInvoke());
switch (method.getName()) {
case "invoke": idx = 0; break;
case "invokeExact": idx = 1; break;
default: throw new InternalError(method.getName());
}
MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
if (mh != null) return mh;
MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
MethodHandle.class, Object[].class);
mh = throwException(type);
mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
if (!method.getInvocationType().equals(mh.type()))
throw new InternalError(method.toString());
mh = mh.withInternalMemberName(method, false);
mh = mh.asVarargsCollector(Object[].class);
assert(method.isVarargs());
FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
return mh;
}
static MethodHandle fakeVarHandleInvoke(MemberName method) {
// TODO caching, is it necessary?
MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class,
VarHandle.class, Object[].class);
MethodHandle mh = throwException(type);
mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle"));
if (!method.getInvocationType().equals(mh.type()))
throw new InternalError(method.toString());
mh = mh.withInternalMemberName(method, false);
mh = mh.asVarargsCollector(Object[].class);
assert(method.isVarargs());
return mh;
}
/**
* Create an alias for the method handle which, when called,
* appears to be called from the same class loader and protection domain
* as hostClass.
* This is an expensive no-op unless the method which is called
* is sensitive to its caller. A small number of system methods
* are in this category, including Class.forName and Method.invoke.
*/
static
MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
return BindCaller.bindCaller(mh, hostClass);
}
// Put the whole mess into its own nested class.
// That way we can lazily load the code and set up the constants.
private static class BindCaller {
static
MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
// Do not use this function to inject calls into system classes.
if (hostClass == null
|| (hostClass.isArray() ||
hostClass.isPrimitive() ||
hostClass.getName().startsWith("java.") ||
hostClass.getName().startsWith("sun."))) {
throw new InternalError(); // does not happen, and should not anyway
}
// For simplicity, convert mh to a varargs-like method.
MethodHandle vamh = prepareForInvoker(mh);
// Cache the result of makeInjectedInvoker once per argument class.
MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
}
private static MethodHandle makeInjectedInvoker(Class<?> hostClass) {
Class<?> bcc = UNSAFE.defineAnonymousClass(hostClass, T_BYTES, null);
if (hostClass.getClassLoader() != bcc.getClassLoader())
throw new InternalError(hostClass.getName()+" (CL)");
try {
if (hostClass.getProtectionDomain() != bcc.getProtectionDomain())
throw new InternalError(hostClass.getName()+" (PD)");
} catch (SecurityException ex) {
// Self-check was blocked by security manager. This is OK.
// In fact the whole try body could be turned into an assertion.
}
try {
MethodHandle init = IMPL_LOOKUP.findStatic(bcc, "init", MethodType.methodType(void.class));
init.invokeExact(); // force initialization of the class
} catch (Throwable ex) {
throw uncaughtException(ex);
}
MethodHandle bccInvoker;
try {
MethodType invokerMT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
bccInvoker = IMPL_LOOKUP.findStatic(bcc, "invoke_V", invokerMT);
} catch (ReflectiveOperationException ex) {
throw uncaughtException(ex);
}
// Test the invoker, to ensure that it really injects into the right place.
try {
MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
Object ok = bccInvoker.invokeExact(vamh, new Object[]{hostClass, bcc});
} catch (Throwable ex) {
throw new InternalError(ex);
}
return bccInvoker;
}
private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
@Override protected MethodHandle computeValue(Class<?> hostClass) {
return makeInjectedInvoker(hostClass);
}
};
// Adapt mh so that it can be called directly from an injected invoker:
private static MethodHandle prepareForInvoker(MethodHandle mh) {
mh = mh.asFixedArity();
MethodType mt = mh.type();
int arity = mt.parameterCount();
MethodHandle vamh = mh.asType(mt.generic());
vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
vamh = vamh.asSpreader(Object[].class, arity);
vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
return vamh;
}
// Undo the adapter effect of prepareForInvoker:
private static MethodHandle restoreToType(MethodHandle vamh,
MethodHandle original,
Class<?> hostClass) {
MethodType type = original.type();
MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
MemberName member = original.internalMemberName();
mh = mh.asType(type);
mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
return mh;
}
private static final MethodHandle MH_checkCallerClass;
static {
final Class<?> THIS_CLASS = BindCaller.class;
assert(checkCallerClass(THIS_CLASS, THIS_CLASS));
try {
MH_checkCallerClass = IMPL_LOOKUP
.findStatic(THIS_CLASS, "checkCallerClass",
MethodType.methodType(boolean.class, Class.class, Class.class));
assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS, THIS_CLASS));
} catch (Throwable ex) {
throw new InternalError(ex);
}
}
@CallerSensitive
private static boolean checkCallerClass(Class<?> expected, Class<?> expected2) {
// This method is called via MH_checkCallerClass and so it's
// correct to ask for the immediate caller here.
Class<?> actual = Reflection.getCallerClass();
if (actual != expected && actual != expected2)
throw new InternalError("found "+actual.getName()+", expected "+expected.getName()
+(expected == expected2 ? "" : ", or else "+expected2.getName()));
return true;
}
private static final byte[] T_BYTES;
static {
final Object[] values = {null};
AccessController.doPrivileged(new PrivilegedAction<>() {
public Void run() {
try {
Class<T> tClass = T.class;
String tName = tClass.getName();
String tResource = tName.substring(tName.lastIndexOf('.')+1)+".class";
try (java.io.InputStream in = tClass.getResourceAsStream(tResource)) {
values[0] = in.readAllBytes();
}
} catch (java.io.IOException ex) {
throw new InternalError(ex);
}
return null;
}
});
T_BYTES = (byte[]) values[0];
}
// The following class is used as a template for Unsafe.defineAnonymousClass:
private static class T {
static void init() { } // side effect: initializes this class
static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
return vamh.invokeExact(args);
}
}
}
/** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
private static final class WrappedMember extends DelegatingMethodHandle {
private final MethodHandle target;
private final MemberName member;
private final Class<?> callerClass;
private final boolean isInvokeSpecial;
private WrappedMember(MethodHandle target, MethodType type,
MemberName member, boolean isInvokeSpecial,
Class<?> callerClass) {
super(type, target);
this.target = target;
this.member = member;
this.callerClass = callerClass;
this.isInvokeSpecial = isInvokeSpecial;
}
@Override
MemberName internalMemberName() {
return member;
}
@Override
Class<?> internalCallerClass() {
return callerClass;
}
@Override
boolean isInvokeSpecial() {
return isInvokeSpecial;
}
@Override
protected MethodHandle getTarget() {
return target;
}
@Override
public MethodHandle asTypeUncached(MethodType newType) {
// This MH is an alias for target, except for the MemberName
// Drop the MemberName if there is any conversion.
return asTypeCache = target.asType(newType);
}
}
static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
return target;
return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
}
/** Intrinsic IDs */
/*non-public*/
enum Intrinsic {
SELECT_ALTERNATIVE,
GUARD_WITH_CATCH,
NEW_ARRAY,
ARRAY_LOAD,
ARRAY_STORE,
IDENTITY,
ZERO,
NONE // no intrinsic associated
}
/** Mark arbitrary method handle as intrinsic.
* InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
private static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
private final MethodHandle target;
private final Intrinsic intrinsicName;
IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
super(target.type(), target);
this.target = target;
this.intrinsicName = intrinsicName;
}
@Override
protected MethodHandle getTarget() {
return target;
}
@Override
Intrinsic intrinsicName() {
return intrinsicName;
}
@Override
public MethodHandle asTypeUncached(MethodType newType) {
// This MH is an alias for target, except for the intrinsic name
// Drop the name if there is any conversion.
return asTypeCache = target.asType(newType);
}
@Override
String internalProperties() {
return super.internalProperties() +
"\n& Intrinsic="+intrinsicName;
}
@Override
public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
if (intrinsicName == Intrinsic.IDENTITY) {
MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength);
MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
return newArray.asType(resultType);
}
return super.asCollector(arrayType, arrayLength);
}
}
static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
if (intrinsicName == target.intrinsicName())
return target;
return new IntrinsicMethodHandle(target, intrinsicName);
}
static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
}
/// Collection of multiple arguments.
private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) {
MethodType type = MethodType.genericMethodType(nargs)
.changeReturnType(rtype)
.insertParameterTypes(0, ptypes);
try {
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type);
} catch (ReflectiveOperationException ex) {
return null;
}
}
private static final Object[] NO_ARGS_ARRAY = {};
private static Object[] makeArray(Object... args) { return args; }
private static Object[] array() { return NO_ARGS_ARRAY; }
private static Object[] array(Object a0)
{ return makeArray(a0); }
private static Object[] array(Object a0, Object a1)
{ return makeArray(a0, a1); }
private static Object[] array(Object a0, Object a1, Object a2)
{ return makeArray(a0, a1, a2); }
private static Object[] array(Object a0, Object a1, Object a2, Object a3)
{ return makeArray(a0, a1, a2, a3); }
private static Object[] array(Object a0, Object a1, Object a2, Object a3,
Object a4)
{ return makeArray(a0, a1, a2, a3, a4); }
private static Object[] array(Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5)
{ return makeArray(a0, a1, a2, a3, a4, a5); }
private static Object[] array(Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6)
{ return makeArray(a0, a1, a2, a3, a4, a5, a6); }
private static Object[] array(Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6, Object a7)
{ return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); }
private static Object[] array(Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6, Object a7,
Object a8)
{ return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); }
private static Object[] array(Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6, Object a7,
Object a8, Object a9)
{ return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); }
private static final int ARRAYS_COUNT = 11;
private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1];
// filling versions of the above:
// using Integer len instead of int len and no varargs to avoid bootstrapping problems
private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) {
Object[] a = new Object[len];
fillWithArguments(a, 0, args);
return a;
}
private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) {
Object[] a = Arrays.copyOf(example, len);
assert(a.getClass() != Object[].class);
fillWithArguments(a, 0, args);
return a;
}
private static void fillWithArguments(Object[] a, int pos, Object... args) {
System.arraycopy(args, 0, a, pos, args.length);
}
// using Integer pos instead of int pos to avoid bootstrapping problems
private static Object[] fillArray(Integer pos, Object[] a, Object a0)
{ fillWithArguments(a, pos, a0); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1)
{ fillWithArguments(a, pos, a0, a1); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2)
{ fillWithArguments(a, pos, a0, a1, a2); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3)
{ fillWithArguments(a, pos, a0, a1, a2, a3); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
Object a4)
{ fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5)
{ fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6)
{ fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6, Object a7)
{ fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6, Object a7,
Object a8)
{ fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; }
private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
Object a4, Object a5, Object a6, Object a7,
Object a8, Object a9)
{ fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; }
private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods
private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT];
private static MethodHandle getFillArray(int count) {
assert (count > 0 && count < FILL_ARRAYS_COUNT);
MethodHandle mh = FILL_ARRAYS[count];
if (mh != null) {
return mh;
}
mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class);
FILL_ARRAYS[count] = mh;
return mh;
}
private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) {
Object a = w.makeArray(boxes.length);
w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length);
return a;
}
/** Return a method handle that takes the indicated number of Object
* arguments and returns an Object array of them, as if for varargs.
*/
static MethodHandle varargsArray(int nargs) {
MethodHandle mh = ARRAYS[nargs];
if (mh != null) {
return mh;
}
if (nargs < ARRAYS_COUNT) {
mh = findCollector("array", nargs, Object[].class);
} else {
mh = buildVarargsArray(getConstantHandle(MH_fillNewArray),
getConstantHandle(MH_arrayIdentity), nargs);
}
assert(assertCorrectArity(mh, nargs));
mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
return ARRAYS[nargs] = mh;
}
private static boolean assertCorrectArity(MethodHandle mh, int arity) {
assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
return true;
}
// Array identity function (used as getConstantHandle(MH_arrayIdentity)).
static <T> T[] identity(T[] x) {
return x;
}
private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) {
// Build up the result mh as a sequence of fills like this:
// finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23))
// The various fill(_,10*I,___*[J]) are reusable.
int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately
int rightLen = nargs - leftLen;
MethodHandle leftCollector = newArray.bindTo(nargs);
leftCollector = leftCollector.asCollector(Object[].class, leftLen);
MethodHandle mh = finisher;
if (rightLen > 0) {
MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen);
if (mh.equals(getConstantHandle(MH_arrayIdentity)))
mh = rightFiller;
else
mh = MethodHandles.collectArguments(mh, 0, rightFiller);
}
if (mh.equals(getConstantHandle(MH_arrayIdentity)))
mh = leftCollector;
else
mh = MethodHandles.collectArguments(mh, 0, leftCollector);
return mh;
}
private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1;
private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1];
/** fill_array_to_right(N).invoke(a, argL..arg[N-1])
* fills a[L]..a[N-1] with corresponding arguments,
* and then returns a. The value L is a global constant (LEFT_ARGS).
*/
private static MethodHandle fillToRight(int nargs) {
MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs];
if (filler != null) return filler;
filler = buildFiller(nargs);
assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1));
return FILL_ARRAY_TO_RIGHT[nargs] = filler;
}
private static MethodHandle buildFiller(int nargs) {
if (nargs <= LEFT_ARGS)
return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged
// we need room for both mh and a in mh.invoke(a, arg*[nargs])
final int CHUNK = LEFT_ARGS;
int rightLen = nargs % CHUNK;
int midLen = nargs - rightLen;
if (rightLen == 0) {
midLen = nargs - (rightLen = CHUNK);
if (FILL_ARRAY_TO_RIGHT[midLen] == null) {
// build some precursors from left to right
for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK)
if (j > LEFT_ARGS) fillToRight(j);
}
}
if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS);
assert(rightLen > 0);
MethodHandle midFill = fillToRight(midLen); // recursive fill
MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1]
assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS);
assert(rightFill.type().parameterCount() == 1 + rightLen);
// Combine the two fills:
// right(mid(a, x10..x19), x20..x23)
// The final product will look like this:
// right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23)
if (midLen == LEFT_ARGS)
return rightFill;
else
return MethodHandles.collectArguments(rightFill, 0, midFill);
}
static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
/** Return a method handle that takes the indicated number of
* typed arguments and returns an array of them.
* The type argument is the array type.
*/
static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
Class<?> elemType = arrayType.getComponentType();
if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
// FIXME: Need more special casing and caching here.
if (nargs >= MAX_JVM_ARITY/2 - 1) {
int slots = nargs;
final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
if (slots > MAX_ARRAY_SLOTS)
throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
}
if (elemType == Object.class)
return varargsArray(nargs);
// other cases: primitive arrays, subtypes of Object[]
MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType);
MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
if (mh != null) return mh;
if (nargs == 0) {
Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0);
mh = MethodHandles.constant(arrayType, example);
} else if (elemType.isPrimitive()) {
MethodHandle builder = getConstantHandle(MH_fillNewArray);
MethodHandle producer = buildArrayProducer(arrayType);
mh = buildVarargsArray(builder, producer, nargs);
} else {
Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class);
Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType);
MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example);
MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed
mh = buildVarargsArray(builder, producer, nargs);
}
mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)));
mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
assert(assertCorrectArity(mh, nargs));
if (nargs < cache.length)
cache[nargs] = mh;
return mh;
}
private static MethodHandle buildArrayProducer(Class<?> arrayType) {
Class<?> elemType = arrayType.getComponentType();
assert(elemType.isPrimitive());
return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType));
}
/*non-public*/ static void assertSame(Object mh1, Object mh2) {
if (mh1 != mh2) {
String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)",
mh1, ((MethodHandle)mh1).form,
mh2, ((MethodHandle)mh2).form);
throw newInternalError(msg);
}
}
// Local constant functions:
/*non-public*/ static final NamedFunction
NF_checkSpreadArgument,
NF_guardWithCatch,
NF_throwException,
NF_profileBoolean;
static {
try {
NF_checkSpreadArgument = new NamedFunction(MethodHandleImpl.class
.getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
NF_guardWithCatch = new NamedFunction(MethodHandleImpl.class
.getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
MethodHandle.class, Object[].class));
NF_throwException = new NamedFunction(MethodHandleImpl.class
.getDeclaredMethod("throwException", Throwable.class));
NF_profileBoolean = new NamedFunction(MethodHandleImpl.class
.getDeclaredMethod("profileBoolean", boolean.class, int[].class));
} catch (ReflectiveOperationException ex) {
throw newInternalError(ex);
}
}
/**
* Assembles a loop method handle from the given handles and type information. This works by binding and configuring
* the {@linkplain #looper(MethodHandle[], MethodHandle[], MethodHandle[], MethodHandle[], int, int, Object[]) "most
* generic loop"}.
*
* @param tloop the return type of the loop.
* @param targs types of the arguments to be passed to the loop.
* @param tvars types of loop-local variables.
* @param init sanitized array of initializers for loop-local variables.
* @param step sanitited array of loop bodies.
* @param pred sanitized array of predicates.
* @param fini sanitized array of loop finalizers.
*
* @return a handle that, when invoked, will execute the loop.
*/
static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<Class<?>> tvars, List<MethodHandle> init,
List<MethodHandle> step, List<MethodHandle> pred, List<MethodHandle> fini) {
MethodHandle[] ainit = toArrayArgs(init);
MethodHandle[] astep = toArrayArgs(step);
MethodHandle[] apred = toArrayArgs(pred);
MethodHandle[] afini = toArrayArgs(fini);
MethodHandle l = getConstantHandle(MH_looper);
// Bind the statically known arguments.
l = MethodHandles.insertArguments(l, 0, ainit, astep, apred, afini, tvars.size(), targs.size());
// Turn the args array into an argument list.
l = l.asCollector(Object[].class, targs.size());
// Finally, make loop type.
MethodType loopType = MethodType.methodType(tloop, targs);
l = l.asType(loopType);
return l;
}
/**
* Converts all handles in the {@code hs} array to handles that accept an array of arguments.
*
* @param hs method handles to be converted.
*
* @return the {@code hs} array, with all method handles therein converted.
*/
static MethodHandle[] toArrayArgs(List<MethodHandle> hs) {
return hs.stream().map(h -> h.asSpreader(Object[].class, h.type().parameterCount())).toArray(MethodHandle[]::new);
}
/**
* This method embodies the most generic loop for use by {@link MethodHandles#loop(MethodHandle[][])}. A handle on
* it will be transformed into a handle on a concrete loop instantiation by {@link #makeLoop}.
*
* @param init loop-local variable initializers.
* @param step bodies.
* @param pred predicates.
* @param fini finalizers.
* @param varSize number of loop-local variables.
* @param nArgs number of arguments passed to the loop.
* @param args arguments to the loop invocation.
*
* @return the result of executing the loop.
*/
static Object looper(MethodHandle[] init, MethodHandle[] step, MethodHandle[] pred, MethodHandle[] fini,
int varSize, int nArgs, Object[] args) throws Throwable {
Object[] varsAndArgs = new Object[varSize + nArgs];
for (int i = 0, v = 0; i < init.length; ++i) {
if (init[i].type().returnType() == void.class) {
init[i].invoke(args);
} else {
varsAndArgs[v++] = init[i].invoke(args);
}
}
System.arraycopy(args, 0, varsAndArgs, varSize, nArgs);
final int nSteps = step.length;
for (; ; ) {
for (int i = 0, v = 0; i < nSteps; ++i) {
MethodHandle p = pred[i];
MethodHandle s = step[i];
MethodHandle f = fini[i];
if (s.type().returnType() == void.class) {
s.invoke(varsAndArgs);
} else {
varsAndArgs[v++] = s.invoke(varsAndArgs);
}
if (!(boolean) p.invoke(varsAndArgs)) {
return f.invoke(varsAndArgs);
}
}
}
}
/**
* This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
* MethodHandle) counting loops}.
*
* @param counter the counter parameter, passed in during loop execution.
* @param limit the upper bound of the parameter, statically bound at loop creation time.
*
* @return whether the counter has reached the limit.
*/
static boolean countedLoopPredicate(int counter, int limit) {
return counter <= limit;
}
/**
* This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
* MethodHandle) counting loops} to increment the counter.
*
* @param counter the loop counter.
*
* @return the loop counter incremented by 1.
*/
static int countedLoopStep(int counter, int limit) {
return counter + 1;
}
/**
* This method is bound as a filter in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, MethodHandle,
* MethodHandle) counting loops} to pass the correct counter value to the body.
*
* @param counter the loop counter.
*
* @return the loop counter decremented by 1.
*/
static int decrementCounter(int counter) {
return counter - 1;
}
/**
* This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}.
*
* @param it the {@link Iterable} over which the loop iterates.
*
* @return an {@link Iterator} over the argument's elements.
*/
static Iterator<?> initIterator(Iterable<?> it) {
return it.iterator();
}
/**
* This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}.
*
* @param it the iterator to be checked.
*
* @return {@code true} iff there are more elements to iterate over.
*/
static boolean iteratePredicate(Iterator<?> it) {
return it.hasNext();
}
/**
* This method is bound as the step for retrieving the current value from the iterator in {@linkplain
* MethodHandles#iteratedLoop iterating loops}.
*
* @param it the iterator.
*
* @return the next element from the iterator.
*/
static Object iterateNext(Iterator<?> it) {
return it.next();
}
/**
* Makes a {@code try-finally} handle that conforms to the type constraints.
*
* @param target the target to execute in a {@code try-finally} block.
* @param cleanup the cleanup to execute in the {@code finally} block.
* @param type the result type of the entire construct.
* @param argTypes the types of the arguments.
*
* @return a handle on the constructed {@code try-finally} block.
*/
static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> type, List<Class<?>> argTypes) {
MethodHandle tf = getConstantHandle(type == void.class ? MH_tryFinallyVoidExec : MH_tryFinallyExec);
// Bind the statically known arguments.
tf = MethodHandles.insertArguments(tf, 0, target, cleanup);
// Turn the args array into an argument list.
tf = tf.asCollector(Object[].class, argTypes.size());
// Finally, make try-finally type.
MethodType tfType = MethodType.methodType(type, argTypes);
tf = tf.asType(tfType);
return tf;
}
/**
* A method that will be bound during construction of a {@code try-finally} handle with non-{@code void} return type
* by {@link MethodHandles#tryFinally(MethodHandle, MethodHandle)}.
*
* @param target the handle to wrap in a {@code try-finally} block. This will be bound.
* @param cleanup the handle to run in any case before returning. This will be bound.
* @param args the arguments to the call. These will remain as the argument list.
*
* @return whatever the execution of the {@code target} returned (it may have been modified by the execution of
* {@code cleanup}).
* @throws Throwable in case anything is thrown by the execution of {@code target}, the {@link Throwable} will be
* passed to the {@code cleanup} handle, which may decide to throw any exception it sees fit.
*/
static Object tryFinallyExecutor(MethodHandle target, MethodHandle cleanup, Object[] args) throws Throwable {
Throwable t = null;
Object r = null;
try {
r = target.invoke(args);
} catch (Throwable thrown) {
t = thrown;
throw t;
} finally {
r = cleanup.invoke(t, r, args);
}
return r;
}
/**
* A method that will be bound during construction of a {@code try-finally} handle with {@code void} return type by
* {@link MethodHandles#tryFinally(MethodHandle, MethodHandle)}.
*
* @param target the handle to wrap in a {@code try-finally} block. This will be bound.
* @param cleanup the handle to run in any case before returning. This will be bound.
* @param args the arguments to the call. These will remain as the argument list.
*
* @throws Throwable in case anything is thrown by the execution of {@code target}, the {@link Throwable} will be
* passed to the {@code cleanup} handle, which may decide to throw any exception it sees fit.
*/
static void tryFinallyVoidExecutor(MethodHandle target, MethodHandle cleanup, Object[] args) throws Throwable {
Throwable t = null;
try {
target.invoke(args);
} catch (Throwable thrown) {
t = thrown;
throw t;
} finally {
cleanup.invoke(t, args);
}
}
// Indexes into constant method handles:
static final int
MH_cast = 0,
MH_selectAlternative = 1,
MH_copyAsPrimitiveArray = 2,
MH_fillNewTypedArray = 3,
MH_fillNewArray = 4,
MH_arrayIdentity = 5,
MH_looper = 6,
MH_countedLoopPred = 7,
MH_countedLoopStep = 8,
MH_iteratePred = 9,
MH_initIterator = 10,
MH_iterateNext = 11,
MH_tryFinallyExec = 12,
MH_tryFinallyVoidExec = 13,
MH_decrementCounter = 14,
MH_LIMIT = 15;
static MethodHandle getConstantHandle(int idx) {
MethodHandle handle = HANDLES[idx];
if (handle != null) {
return handle;
}
return setCachedHandle(idx, makeConstantHandle(idx));
}
private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) {
// Simulate a CAS, to avoid racy duplication of results.
MethodHandle prev = HANDLES[idx];
if (prev != null) {
return prev;
}
HANDLES[idx] = method;
return method;
}
// Local constant method handles:
private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT];
private static MethodHandle makeConstantHandle(int idx) {
try {
switch (idx) {
case MH_cast:
return IMPL_LOOKUP.findVirtual(Class.class, "cast",
MethodType.methodType(Object.class, Object.class));
case MH_copyAsPrimitiveArray:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray",
MethodType.methodType(Object.class, Wrapper.class, Object[].class));
case MH_arrayIdentity:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity",
MethodType.methodType(Object[].class, Object[].class));
case MH_fillNewArray:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray",
MethodType.methodType(Object[].class, Integer.class, Object[].class));
case MH_fillNewTypedArray:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray",
MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class));
case MH_selectAlternative:
return makeIntrinsic(IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class)),
Intrinsic.SELECT_ALTERNATIVE);
case MH_looper:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "looper", MethodType.methodType(Object.class,
MethodHandle[].class, MethodHandle[].class, MethodHandle[].class, MethodHandle[].class,
int.class, int.class, Object[].class));
case MH_countedLoopPred:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate",
MethodType.methodType(boolean.class, int.class, int.class));
case MH_countedLoopStep:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep",
MethodType.methodType(int.class, int.class, int.class));
case MH_iteratePred:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate",
MethodType.methodType(boolean.class, Iterator.class));
case MH_initIterator:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator",
MethodType.methodType(Iterator.class, Iterable.class));
case MH_iterateNext:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext",
MethodType.methodType(Object.class, Iterator.class));
case MH_tryFinallyExec:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "tryFinallyExecutor",
MethodType.methodType(Object.class, MethodHandle.class, MethodHandle.class, Object[].class));
case MH_tryFinallyVoidExec:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "tryFinallyVoidExecutor",
MethodType.methodType(void.class, MethodHandle.class, MethodHandle.class, Object[].class));
case MH_decrementCounter:
return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "decrementCounter",
MethodType.methodType(int.class, int.class));
}
} catch (ReflectiveOperationException ex) {
throw newInternalError(ex);
}
throw newInternalError("Unknown function index: " + idx);
}
}